The most expensive private art collection in the world belongs to billionaire David Lawrence Geffen, the founder of DreamWorks Animation, according to Wealth-X, which compiles information on ultra-high-net-worth individuals.

Wealth-X released a list of the top 10 billionaire art collectors worldwide. The collections have a combined worth of $9.18 billion, or about 18 percent of the group’s net wealth. Of the world’s 2,170 billionaires, the average holding in art is worth $31 million or 0.5 percent of their net worth, according to Wealth-X.

The top 10 have a much higher portion of their wealth tied up in art.

Geffen has the most expensive collection at $1.1 billion, which is 20 percent of his $5.5 billion fortune. Geffen collects American artists. He reportedly sold four pieces of his contemporary art collection in 2006 for $421 million. The sale included a drip painting, Number 5, 1948 by Jackson Pollock, that sold for $140 million and Woman III by Willem De Kooning that brought $137.5 million.

Nasser David Khalili, a British-Iranian property tycoon, is sixth on the list for the value of his collection, and is at the top of the list in terms of the size of his colleciton. Also known as the "Secrete Sultan," Khalili has the heaviest weighting of art in his portfolio of any of the top collectors.

Almost all of his $1 billion fortune is invested in his $930 million art collection. He has liquid assets of cash and investments of around $70 million or 7 percent of his wealth, according to Wealth-X. Much of his 25,000-piece collection is exhibited in public museums. He specializes in Islamic works, Japanese and Swedish art, and ceramics.

The owner of Christie’s auction house, Francois Pinault, is the wealthiest person on the top 10 list with a fortune of $9.9 billion. His art collection accounts for $1 billion of that wealth or a little more than 10 percent. It is made up of at least 2,000 pieces, including works by Picasso, Mondrian and Jeff Koons.

Following Geffen, the most valuable collections belong to Steven A. Cohen, Eli Broad and Boris (Bidzina) Ivanishvili, each of whom has $1 billion invested in art. That represents 12 percent of Cohen’s $8.3 billion fortune, 16.7 percent of Broad’s $6 billion wealth and 15.6 percent of Ivanishvili’s $6.4 billion worth.

The seventh and eighth most valuable collections belong to Norman L. Braman with $900 million in art, or 56.3 percent of his $1.6 billion fortune, and Doris F. Fisher with an $800 million art collection, or 34.8 percent of her $2.3 billion worth.

Leonard David Black has a $750 million collection that represents 22.1 percent of his $3.4 billion worth and Samuel Irving Newhouse Jr. has a $700 million collection that is 9.9 percent of his $7.1 billion worth.